In a base station antenna apparatus for a mobile communication system, it is necessary to adjust the directivity in a vertical plane to form an appropriate communication area. Accordingly, for example, in an array antenna according to Patent Literature 1, the beam tilt angle is changed by adjusting a phase shifting device that is arranged in a feed circuit.
On the other hand, in Patent Literature 2, for example, an adaptive array antenna apparatus is disclosed, which includes a configuration in which phase and amplitude changing means, which is means for changing a phase and an amplitude of a signal of a radio signal frequency in a digital or an analog manner, is arranged for each antenna, and the phase shift quantity of the phase shifting device is controlled so that the directivity adapted to an estimated incoming direction of a specific radio signal frequency is implemented.